Optical touch device and locating method thereof

ABSTRACT

An optical touch device includes a light guide module including a first light guide component, a second light guide component, a third light guide component and a fourth light guide component, a light source module including a first light emitting component and a second light emitting component for emitting light alternately and an image detecting module disposed between two neighboring ends of the first light guide component and the second light guide component. The third light guide component and the fourth light guide component are mirror light guide components. A field of view of the image detecting module covers the third light guide component and the fourth light guide component. The optical touch device can avoid a blind zone and can be used as a dual-touch device or a multi-touch device. A locating method and a linear source module are also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromthe prior Taiwanese Patent Application No. 098131423, filed Sep. 17,2009, the entire contents of which are incorporated herein by reference.

BACKGROUND

1. Field of the Invention

The present invention relates to a touch device, and particularly to anoptical touch device and a locating method thereof, and a linear lightsource module.

2. Description of the Related Art

Nowadays, a touch function has been one of necessary functions of manyelectronic devices. A touch device is an important component to achievethe touch function. Generally, a familiar type of the touch device is,for example, a resistive touch device, a capacitive touch device or anoptical touch device. The electronic devices can be equipped withvarious touch devices in accordance with the various demands.

FIG. 1 is a schematic view of a conventional optical touch device.Referring to FIG. 1, the conventional optical touch device 100 includesa light guide module 110, a light emitting component 120 and an imagedetecting module 130. The light guide module 110 includes two lightguide bars 112 a and 112 b and a mirror bar 114. The light guide bars112 a and 112 b and the mirror bar 114 are arranged along three sides ofa rectangle. The light guide bar 112 a faces to the mirror bar 114 andthe light guide bar 112 b is connected between the light guide bar 112 aand mirror bar 114. The area in the rectangle defines a detecting area116. In addition, the light emitting component 120 is disposed betweentwo neighboring ends of the light guide bar 112 a and the light guidebar 112 b and is configured for emitting light into the light guide bar112 a and the light guide bar 112 b. The light guide bar 112 a and thelight guide bar 112 b are configured for converting the light from thelight emitting component 120 into a linear light to irradiate thedetecting area 116. The image detecting module 130 is disposed besidesthe light guide bar 112 a. A field of view (FOV) of the image detectingmodule 130 covers the detecting area 116.

The image detecting module 130 is configured for detecting a touch point(i.e., a light blocking object) in the detecting area 116 andcalculating a position of the touch point. In detail, the touch point Ain the detecting area 116 has a mirror point A1 formed by the mirror bar114. Meanwhile, the image detecting module 130 can detect dark points A2and A3. Thus, distances d1 and d2 can be calculated. Then, according tothe distances d1 and d2 and other known parameters, the position (i.e.,coordinates) of the touch point A can be calculated. The other knownparameters mentioned above include a length of the detecting area 116along the X axis, a width of the detecting area 116 along the Y axis, ashortest distance between the touch point A and the mirror bar 114 thatis equal to a shortest distance between the mirror point A and themirror bar 114, and so on. A detailed calculating method of the positionof the touch point A is familiar to one skilled in the art and is not bedescribed here.

However, the conventional optical touch device 100 has a blind zone 150as shown in FIG. 1. The blind zone 150 refers to an area in thedetecting area 116 where the coordinates of the touch point can not becalculated accurately. For example, the touch point B in the detectingarea 116 is just located in the blind zone 150 so that the dark pointsB2 and B3 detected by the image detecting module 130 are overlappedpartially. Thus, the coordinates of the touch point B can not becalculated accurately.

FIG. 2 is a schematic view of another conventional optical touch device.Referring to FIG. 2, the conventional optical touch device 100 a issimilar to the conventional optical touch device 100 except that thelight guide module 110 a includes two light guide bars 112 a and 112 band two mirror bars 114 a and 114 b. The light guide bar 112 a isadjacent to the light guide bar 112 b, and the mirror bar 114 a isadjacent to the mirror bar 114 b. The light guide bars 112 a and 112 band the mirror bars 114 a and 114 b are arranged along four sides of arectangle. The area in the rectangle defines a detecting area 116.

Comparative to the conventional optical touch device 100, although thearea of the blind zone 150 a of the conventional optical touch device100 a has been decreased, the problem of the blind zone as mentionedabove still exists. In addition, because the light guide module 110 a ofthe conventional optical touch device 100 a includes two mirror bars 114a and 114 b, one touch point in the detecting area 116 will generatethree mirror points correspondingly. Thus, the image detecting module130 will detect more dark points than the conventional optical touchdevice 100, thereby increasing the complexity of calculating thecoordinates of the one touch point.

Furthermore, when two touch points are simultaneously in the detectingarea 116, six mirror points corresponding to the two touch points willgenerate. Thus, the complexity of calculating the coordinates of the twotouch points will be increased greatly. Therefore, the conventionaloptical touch device 100 a is unsuitable to be used as a dual-touchdevice or a multi-touch device.

BRIEF SUMMARY

The present invention provides an optical touch device to avoid aproblem of a blind zone.

The present invention also provides a locating method of an opticaltouch device so as to solve a problem of a blind zone effectively.

The present invention further provides a linear light source module thatis capable of supplying a linear light and has a mirror function.

To achieve the above-mentioned advantages, the present inventionprovides an optical touch device including a light guide module, a lightsource module and an image detecting module. The light guide moduleincludes a first light guide component, a second light guide component,a third light guide component and a fourth light guide componentarranged along four sides of a rectangle. The first light guidecomponent, the second light guide component, the third light guidecomponent and the fourth light guide component defines a detecting areatherebetween. The first light guide component faces to the third lightguide component, and the second light guide component faces to thefourth light guide component. Each of the first light guide componentand the second light guide component has a first surface facing to thedetecting area. Each of the third light guide component and the fourthlight guide component is a mirror light guide component. The mirrorlight guide component includes a light emitting end facing to thedetecting area, a second surface opposite to the light emitting end, anda light incident end between the light emitting end and the secondsurface. The second surface has a mirror light reflecting layer formedthereon. The light source module includes a first light emittingcomponent and a second light emitting component. The first lightemitting component is configured for providing light to the lightincident end of the third light guide component. The second lightemitting component is configured for providing light to the lightincident end of the fourth light guide component. The first lightemitting component and the second light emitting component areconfigured for emitting light alternately. The first surfaces of thefirst light guide component and the second light guide component areconfigured for guiding the light to the detecting area. The imagedetecting module is disposed between two neighboring ends of the firstlight guide component and the second light guide component. A field ofview of the image detecting module covers the detecting area, the thirdlight guide component and the fourth light guide component.

In one embodiment provided by the present invention, each of the firstlight guide component and the second light guide component is a lightguide bar. The light guide bar further has a reflecting surface oppositeto the first surface and a light incidence surface connected between thefirst surface and the reflecting surface. The first surface is a lightemitting surface. The light source module is further configured forproviding light to the light incident surfaces of the first light guidecomponent and the second light guide component.

In one embodiment provided by the present invention, the first lightemitting component is disposed between two neighboring ends of thesecond light guide component and the third light guide component. Thefirst light emitting component is further configured for providing lightto the light incidence surface of the second light guide component. Thesecond light emitting component is disposed between two neighboring endsof the fourth light guide component and the first light guide component.The second light emitting component is further configured for providinglight to the light incidence surface of the first light guide component.

In one embodiment provided by the present invention, each of the firstlight guide component and the second light guide component is a lightreflecting bar. The first surface of the light reflecting bar is a lightreflecting surface. The light source module further includes a thirdlight emitting component disposed between two neighboring ends of thefirst light guide component and the second light guide component. Thethird light emitting component is configured for providing light to thedetecting area. The light reflecting bar is configured for reflectingthe light arriving at the first surface to the detecting area.

In one embodiment provided by the present invention, the third lightemitting component is a light emitting diode.

In one embodiment provided by the present invention, the mirror lightguide component is either a solid pillar or a hollow pillar.

In one embodiment provided by the present invention, the mirror lightguide component is a semi-cylindrical pillar. The light emitting end ofthe mirror light guide component is a curve surface adjacent to thesecond surface.

In one embodiment provided by the present invention, the mirror lightguide component is hollow. Each of the light incidence end and the lightemitting end of the mirror light guide component is either an opening ora transparent layer.

In one embodiment provided by the present invention, the second surfaceof the mirror light guide component is either a curve surface or a flatsurface.

In one embodiment provided by the present invention, the optical touchdevice further includes a substrate. The light guide module and thelight source module are disposed on the substrate.

In one embodiment provided by the present invention, the first lightemitting component and the second light emitting component are a lightemitting diode respectively.

To achieve the above-mentioned advantages, the present invention alsoprovides a locating method of an optical touch device for aforesaid theoptical touch device. Firstly, the first light emitting component andthe second light emitting component is controlled to emit lightalternately. When the first light emitting component is lighted and thesecond light emitting component is closed, the image detecting moduledetects a first optical information. When the first light emittingcomponent is closed and the second light emitting component is lighted,the image detecting module detects a second optical information. Then,the position of the touch point in the detecting area is determinedaccording to the first optical information and the second opticalinformation detected by the image detecting module.

To achieve the above-mentioned advantages, the present invention furtherprovides a linear light source module including a mirror light guidecomponent and a light emitting component. The mirror light guidecomponent has a light emitting end, a surface opposite to the lightemitting end and a light incidence end connected between the lightemitting end and the surface. The surface has a mirror light reflectinglayer formed thereon. The light emitting component is configured forproviding light to the light incidence end of the mirror light guidecomponent. When the light emitting component is lighted, the mirrorlight guide component is configured for converting the light from thelight emitting component into a linear light to emit from the lightemitting end. When the light emitting component is closed, the mirrorlight guide component is configured for providing a mirror function.

In the optical touch device of the present invention, the third lightguide component and the fourth light guide component of the light guidemodule are the mirror light guide components, and the first lightemitting component and the second light emitting component areconfigured for emitting light alternately. When the third light guidecomponent provides a mirror function, the fourth light guide provides alight guide function. When the fourth light guide provides a mirrorfunction, the third light guide component provides a light guidefunction. Thus, the image detecting module can detect effective andavailable optical information, and thereby avoiding the problem of theblind zone. In addition, the locating method of the optical touch deviceof the present invention includes the step of controlling the firstlight emitting component and the second light emitting component to emitlight alternately. Thus, the image detecting module can detect theeffective and available optical information including the first opticalinformation and the second optical information. The position of thetouch point in the detecting area can be calculated in accordance withthe first optical information and the second optical information, andthereby solving the problem of the blind zone. Further, the linear lightsource module of the present invention has two functions. The linearlight source module can be used to provide a linear light on thecondition that the light emitting component is lighted. Also, becausethe mirror light reflecting layer is formed on the surface of the mirrorlight guide component, the linear light source module can has a mirrorfunction on the condition that the light emitting component is closed.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the various embodimentsdisclosed herein will be better understood with respect to the followingdescription and drawings, in which like numbers refer to like partsthroughout, and in which:

FIG. 1 is a schematic view of a conventional optical touch device.

FIG. 2 is a schematic view of another conventional optical touch device.

FIG. 3 is a schematic view of an optical touch device in accordance witha first embodiment of the present invention.

FIG. 4 is a schematic view of a light guide bar in accordance with anembodiment of the present invention.

FIG. 5 is a schematic view of a mirror light guide component inaccordance with an embodiment of the present invention.

FIG. 6 is a schematic view of a mirror light guide component inaccordance with another embodiment of the present invention.

FIG. 7 is a schematic view of a mirror light guide component inaccordance with further another embodiment of the present invention.

FIG. 8 is a schematic view of a state of the optical device shown inFIG. 2 when the first light emitting component is lighted and the secondlight emitting component is closed.

FIG. 9 is a schematic view of a state of the optical device shown inFIG. 2 when the first light emitting component is closed and the secondlight emitting component is lighted.

FIG. 10 is a schematic view of a status of the optical device shown inFIG. 2 when two touch points are applied on the optical device and thefirst light emitting component is lighted and the second light emittingcomponent is closed.

FIG. 11 is a schematic view of a status of the optical device shown inFIG. 2 when two touch points are applied on the optical device and thefirst light emitting component is closed and the second light emittingcomponent is lighted.

FIG. 12 is a schematic view of an optical touch device in accordancewith a second embodiment of the present invention.

DETAILED DESCRIPTION

FIG. 3 is a schematic view of an optical touch device in accordance witha first embodiment of the present invention. Referring to FIG. 3, in thepresent embodiment, the optical touch device 200 includes a light guidemodule 210, a light source module 220 and an image detecting module 230.The light guide module 210 includes a first light guide component 212, asecond light guide component 214, a third light guide component 216 anda fourth light guide component 218 arranged along four sides of arectangle. The first light guide component 212, the second light guidecomponent 214, the third light guide component 216 and the fourth lightguide component 218 defines a detecting area 219 therebetween. The firstlight guide component 212 faces to the third light guide component 216,and the second light guide component 214 faces to the fourth light guidecomponent 218. The light source module 220 is configured for providinglight to the third light guide component 216 and the fourth light guidecomponent 218. A field of view of the image detecting module 230 coversthe detecting area 219, the third light guide component 216 and thefourth light guide component 218.

In the present embodiment, each of the first light guide component 212and the second light guide component 214 is, for example, a light guidebar 300 as shown in FIG. 4. The light guide bar 300 has a first surface311, a light reflecting surface 312 opposite to the first surface 311and a light incidence surface 313 connected between the first surface311 and the light reflecting surface 312. The first surface 311 servesas a light emitting surface. The light from the light source module 220enters into the light guide bar 300 through the light incidence surface313, then is reflected by the light reflecting surface 312, and finallyemits from the first surface 311 (i.e., the light emitting surface).Referring FIG. 3 and FIG. 4, in the present embodiment, each of thefirst light guide component 212 and the second light guide component 214is a light guide bar 300 as shown in FIG. 4. The first surface 311 ofthe first light guide component 212 and the first surface 311 of thesecond light guide component 214 face to the detecting area 219respectively. The light source module 220 is configured for providinglight to the light incidence surface 313 of the first light guidecomponent 212 and the light incidence surface 313 of the second lightguide component 214 respectively. The light reflecting surface 312 ofthe first light guide component 212 and the light reflecting surface 312of the second light guide component 214 are configured for reflectingthe light to the first surface 311 of the first light guide component212 and the first surface 311 of the second light guide component 214respectively. Then, the light emits from the first surface 311 of thefirst light guide component 212 and the first surface 311 of the secondlight guide component 214 to the detecting area 219 respectively.

Each of the third light guide component 216 and the fourth light guidecomponent 218 is, for example, a mirror light guide component 400 asshown in FIG. 5. The mirror light guide component 400 includes a lightemitting end 411, a second surface 412 opposite to the light emittingend 411, and a light incident end 413 connected between the lightemitting end 411 and the second surface 412. The second surface 412 hasa mirror light reflecting layer (not shown) formed thereon. When thelight enters into the mirror light guide component 400 through the lightincidence end 413, the mirror light reflecting layer on the secondsurface 412 can reflect the light to emit from the light emitting end411. When no light enters into the mirror light guide component 400through the light incidence end 413, the mirror light reflecting layeron the second surface 412 can provide a mirror function.

In the present embodiment, the mirror light guide component 400 is, forexample, a semi-cylindrical pillar and is solid. The light emitting end411 of the mirror light guide component 400 is a curve surface adjacentto the second surface 412. The second surface 412 is, for example, aflat surface. It is noted that the mirror light guide component 400 alsocan be hollow. In addition, the configuration of the mirror light guidecomponent 400 is not limited by the aforesaid configuration. The mirrorlight guide component 400 can be either a solid pillar or a hollowpillar with suitable cross section configuration, and the second surface412 can be a curve surface. Referring FIG. 3 and FIG. 5, in the presentembodiment, each of the third light guide component 216 and the fourthlight guide component 218 is a mirror light guide component 400 as shownin FIG. 5. The light emitting end 411 of the third light guide component216 and the light emitting end 411 of the fourth light guide component218 face to the detecting area 219 respectively. The light source module220 is configured for providing light to the light incidence end 413 ofthe third light guide component 216 and the light incidence end 413 ofthe fourth light guide component 218 respectively.

FIG. 6 is a schematic view of a mirror light guide component inaccordance with another embodiment of the present invention. Referringto FIG. 6, the mirror light guide component 400 a has a similar functionto the mirror light guide component 400. The difference of the mirrorlight guide component 400 a and the mirror light guide component 400 isthe configuration. In detail, in the present embodiment, the mirrorlight guide component 400 a is hollow. The mirror light guide component400 a includes four plates 401, 402, 403 and 404. The light incidenceend 413 and the light emitting end 411 of the mirror light guidecomponent 400 a are an opening respectively. The second surface 412faces to the light emitting end 411, and has a mirror light reflectinglayer formed thereon. Referring FIG. 3 and FIG. 6, in the presentembodiment, each of the third light guide component 216 and the fourthlight guide component 218 is a mirror light guide component 400 a asshown in FIG. 6. The light emitting end 411 of the third light guidecomponent 216 and the light emitting end 411 of the fourth light guidecomponent 218 face to the detecting area 219 respectively. The lightsource module 220 is configured for providing light to the lightincidence end 413 of the third light guide component 216 and the lightincidence end 413 of the fourth light guide component 218 respectively.

FIG. 7 is a schematic view of a mirror light guide component inaccordance with further another embodiment of the present invention.Referring to FIG. 7, the mirror light guide component 400 b is similarto the mirror light guide component 400 a except that the lightincidence end 413 and the light emitting end 411 are respectively atransparent layer. In detail, in the present embodiment, the mirrorlight guide component 400 b is hollow. The mirror light guide component400 b includes four plates 401, 402, 403 and 404 and two transparentlayers 405 and 406. The light incidence end 413 of the mirror lightguide component 400 b is the transparent layer 405 and the lightemitting end 411 of the mirror light guide component 400 b is thetransparent layer 406. Referring FIG. 3 and FIG. 7, in the presentembodiment, each of the third light guide component 216 and the fourthlight guide component 218 is a mirror light guide component 400 b asshown in FIG. 7. The light emitting end 411 of the third light guidecomponent 216 and the light emitting end 411 of the fourth light guidecomponent 218 face to the detecting area 219 respectively. The lightsource module 220 is configured for providing light to the lightincidence end 413 of the third light guide component 216 and the lightincidence end 413 of the fourth light guide component 218 respectively.The light from the light source module 220 can enter into the lightincidence end 413 of the third light guide component 216 and the lightincidence end 413 of the fourth light guide component 218, and then emitfrom light emitting end 411 of the third light guide component 216 andthe light emitting end 411 of the fourth light guide component 218 tothe detecting area 219. The transparent layers 405 and 406 can be madeof a transparent material such as a plastic film or a glass.

Again, referring to FIG. 3, the light source module 220 includes, forexample, a first light emitting component 222 and a second lightemitting component 224. In the present embodiment, the first lightemitting component 222 is, for example, disposed between two neighboringends of the second light guide component 214 and the third light guidecomponent 216. The first light emitting component 222 and the thirdlight guide component 216 form a linear light source module. The firstlight emitting component 222 is configured for providing light to thelight incident end 413 of the third light guide component 216 andproviding light to the light incidence surface 313 of the second lightguide component 214. The second light emitting component 224 is, forexample, disposed between two neighboring ends of the fourth light guidecomponent 218 and the first light guide component 212. The second lightemitting component 224 and the fourth light guide component 218 formanother linear light source module. The second light emitting component224 is configured for providing light to the light incident end 413 ofthe fourth light guide component 218 and providing light to the lightincidence surface 313 of the first light guide component 212. In anotherembodiment, the light can be provided to the first light guide component212 and the second component 214 by other light emitting componentsexcept the first light emitting component 222 and the second lightemitting component 224.

The first light emitting component 222 and the second light emittingcomponent 224 are configured for emitting light alternately. When thefirst light emitting component 222 is lighted and the second lightemitting component 224 is closed, the first light emitting component 222provides the light to the third light guide component 216. The thirdlight guide component 216 then converts the light into a linear light tothe detecting area 219. Meanwhile, the fourth light guide component 218provides a mirror function because the second light emitting component224 is closed. In contrast, when the first light emitting component 222is closed and the second light emitting component 224 is lighted, thesecond light emitting component 224 provides the light to the fourthlight guide component 218. The fourth light guide component 218 thenconverts the light into a linear light to the detecting area 219.Meanwhile, the third light guide component 216 provides a mirrorfunction because the first light emitting component 2222 is closed.

The image detecting module 230 is disposed between two neighboring endsof the first light guide component 212 and the second light guidecomponent 214. A field of view of the image detecting module 230 coversthe detecting area 219, the third light guide component 216 and thefourth light guide component 218. Thus, the image detecting module 230can effectively detect optical information about the touch point in thedetecting area 219 and optical information about the mirror point of thetouch point formed by the third light guide component 216 or the fourthlight guide component 218. According to the optical information, theposition of the touch point in the detecting area 219 can be determinedaccurately.

Additionally, the optical touch device 200 can further includes asubstrate (not shown). The light guide module 210 and the light emittingmodule 220 can be disposed on the substrate.

A locating method of an optical touch device for the optical touchdevice 200 will be described. The locating method includes the followingsteps.

Firstly, the first light emitting component 222 and the second lightemitting component 224 of the optical touch device 200 is controlled toemit light alternately. When the first light emitting component 222 islighted and the second light emitting component 224 is closed, the imagedetecting module 230 detects a first optical information. When the firstlight emitting component 222 is closed and the second light emittingcomponent 224 is lighted, the image detecting module 230 detects asecond optical information.

Secondly, the position of the touch point in the detecting area 219 isdetermined according to the first optical information and the secondoptical information detected by the image detecting module 230.

In detail, referring to FIG. 8, when the first light emitting component222 is lighted and the second light emitting component 224 is closed,the fourth light guide component 218 provides a mirror function. Thus, atouch point C in the detecting area 219 can generate a mirror point C1.The image detecting module 230 can detect a first optical information(e.g., the dark points C2 and C3) about the touch point C and the mirrorpoint C1. Thus, distances d3, d4 can be calculated. Then, according tothe distances d3, d4 and other known parameters, the position (i.e., thecoordinates) of the touch point C can be calculated. The other knownparameters mentioned above include a length of the detecting area 219along the X axis, a width of the detecting area 219 along the Y axis, ashortest distance between the touch point C and the fourth light guidecomponent 218 that is equal to a shortest distance between the mirrorpoint C1 and the fourth light guide component 218, and so on. A detailedcalculating method of the position of the touch point C is familiar toone skilled in the art and is not be described here.

In addition, when the first light emitting component 222 is closed andthe second light emitting component 224 is lighted, the third lightguide component 216 provides a mirror function. Thus, the touch point Cin the detecting area 219 can generate a mirror point C4. The imagedetecting module 230 can detect a second optical information (e.g., thedark points C5 and C6) about the touch point C and the mirror point C4.Thus, distances d5, d6 can be calculated. Then, according to thedistances d5, d6 and other known parameters, the position (i.e., thecoordinates) of the touch point C can be calculated.

And then, according to the first optical information and the secondoptical information detected by the image detecting module 230, theposition of the touch point C in the detecting area 219 can bedetermined. Generally, the exact position of the touch point C can bedetermined by the first optical information and the second opticalinformation respectively.

However, as mentioned above, when the optical touch device only has onemirror component, the optical touch device will generate a blind zone.In the present embodiment, when the first light emitting component 222of the optical touch device 200 is lighted and the second light emittingcomponent 224 of the optical touch device 200 is closed, the imagedetecting module 230 can not detect the effective and available firstoptical information about the touch point in the blind zone of thedetecting area 219. But, when the first light emitting component 222 isclosed and the second light emitting component 224 is lighted, the touchpoint will not be in the blind zone. That is, the image detecting module230 can detect the effective and available second optical informationabout the touch point in the detecting area 219. According to the secondoptical information detected by the image detecting module 230, theposition of the touch point in the detecting area 219 can be calculated.And vice versa. In other words, the blind zone of the optical touchdevice 200 in the state as shown in FIG. 8 is different from the blindzone of the optical touch device 200 in the state as shown in FIG. 9.When one of the first optical information and the second opticalinformation can not be detected, the position of the touch point in thedetecting area 219 still can be calculated accurately by the other oneof the first optical information and the second optical information thatcan be detected. Therefore, the optical touch device 200 in the presentembodiment and the locating method thereof can avoid the blind zoneeffectively.

It is noted that the optical touch device 200 in the present embodimentand the locating method thereof can be applied to a field of doubletouch or a field of multi touch. For example, the optical touch device200 is used as a dual-touch device in the following description.

The locating method of the optical touch device 200 used as thedual-touch device is similar to the aforesaid locating method of theoptical touch device 200 used as a single-touch device. When two touchpoints is applied to the optical touch device 200, a ghost imagephenomenon may be generated. Herein, the locating method of the opticaldouble touch device 200 used as the dual-touch device is described onthe condition that the ghost image phenomenon is generated. FIG. 10 andFIG. 11 are respectively a schematic view of a state of the opticaltouch device 200 used as the dual-touch device.

Referring to FIG. 10, when the first light emitting component 222 islighted and the second light emitting component 224 is closed, thefourth light guide component 218 provides a mirror function. Thus, twotouch points E, F in the detecting area 219 can generate twocorresponding mirror points E1, F1. The image detecting module 230 candetect the first optical information (e.g., the dark points M1, E2, F2)about the touch points E, F and the mirror points E1, F1. Because thedark point M1 is formed by two overlapped dark points, the positions ofthe touch points E, F and a ghost image point G1 can be calculatedaccording to the first optical information. It is noted that the ghostimage point G1 does not exist actually. Thus, the positions of the touchpoints E, F can not be determined accurately.

Referring to FIG. 11, when the first light emitting component 222 isclosed and the second light emitting component 224 is lighted, the thirdlight guide component 216 provides a mirror function. Thus, the twotouch points E, F in the detecting area 219 can generate twocorresponding mirror points E3, F3. The image detecting module 230 candetect the second optical information (e.g., the dark points M2, E4, F4)about the touch points E, F and the mirror points E3, F3. Because thedark point M2 is formed by two overlapped dark points, the positions ofthe touch points E, F and a ghost image point G2 can be calculated bythe second optical information. It is noted that the ghost image pointG2 does not exist actually yet. Because the positions calculatedaccording to the first optical information and the positions calculatedaccording to the second optical information both include the positionsof the touch points E, F. Thus, the positions of the touch points E, Fcan be accurately determined by excluding the positions of the ghostimage points G1, G2.

The optical touch device 200 and the locating method thereof utilize adesign of the first light emitting component 222 and the second lightemitting component 224 emitting light alternately, thereby acquiring thefirst optical information and the second optical information. Accordingto the first optical information and the second optical information, theposition of the touch point can be calculated accurately and simply.Therefore, the optical touch device 200 and the locating method thereofare suitable to be used in the field of dual-touch or multi touch.

FIG. 12 is a schematic view of an optical touch device in accordancewith a second embodiment of the present invention. Referring to FIG. 12,the optical touch device 200 a is similar to the optical touch device200 in the first embodiment except that the first light guide component212′ and the second light guide component 214′ are respectively a lightreflecting bar. The light reflecting bar has a light reflecting surface511. In the present embodiment, the first surface of the first lightguide component 212′ and the first surface of the second light guidecomponent 214′ respectively serve as the light reflecting surface 511.The light source module 220′ further includes a third light emittingcomponent 226 disposed between two neighboring ends of the first lightguide component 212′ and the second light guide component 214′. Thethird light emitting component 226 is configured for providing light tothe detecting area 219. When the optical touch device 200 a works, thethird light emitting component 226 will emit light continuously, and thefirst light guide component 212′ and the second light guide component214′ are configured for reflecting the light arriving at the firstsurfaces thereof (i.e., the light reflecting surfaces 511) to thedetecting area 219. In addition, in the present embodiment, the firstlight emitting component 222 of the optical touch device 200 a is, forexample, configured for only providing light to the third light guidecomponent 216, and the second light emitting component 224 of theoptical touch device 200 a is, for example, configured for onlyproviding light to the fourth light guide component 218.

The advantageous of the optical touch device 200 a in the presentembodiment is similar to the advantageous of the optical touch device200 in the first embodiment, and is not be described here.

In summary, the present invention has at least the following advantages:

1. The optical touch device has different blind zones when the firstlight emitting component is lighted and when the second light emittingcomponent is lighted. Thus, when one of the first optical informationand the second optical information can not be detected, the position ofthe touch point still can be calculated by the other one of the firstoptical information and the second optical information that can bedetected. Therefore, the optical touch device and the locating methodthereof can solve the problem of the blind zone effectively.

2. The optical touch device can be used as a dual-touch device or amulti-touch device. Because the first optical information and the secondoptical information detected by the image detecting module include lessinformation (e.g., less dark points), the complexity of calculating theexact positions of the touch points can be reduce. Therefore, theoptical touch device and the locating method thereof are suitable to beused in the field of dual-touch or multi-touch.

3. The linear light source module can be used to provide a linear lighton the condition that the light emitting component is lighted. Also,because the mirror reflecting layer is formed on the surface of themirror light guide component, the linear light source module can has amirror function on the condition that the light emitting component isclosed.

The above description is given by way of example, and not limitation.Given the above disclosure, one skilled in the art could devisevariations that are within the scope and spirit of the inventiondisclosed herein, including configurations ways of the recessed portionsand materials and/or designs of the attaching structures. Further, thevarious features of the embodiments disclosed herein can be used alone,or in varying combinations with each other and are not intended to belimited to the specific combination described herein. Thus, the scope ofthe claims is not to be limited by the illustrated embodiments.

What is claimed is:
 1. An optical touch device , comprising: a lightguide module comprising a first light guide component, a second lightguide component, a third light guide component and a fourth light guidecomponent arranged along four sides of a rectangle, the first lightguide component, the second light guide component, the third light guidecomponent and the fourth light guide component defining a detecting areatherebetwen, the first light guide component facing to the third lightguide component, the second light guide component facing to the fourthlight guide component, each of the first light guide component and thesecond light guide component having a first surface facing to thedetecting area, each of the third light guide component and the fourthlight guide component being a mirror light guide component, the mirrorlight guide component comprising a light emitting end facing to thedetecting area, a second surface opposite to the light emitting end, anda light incident end connected between the light emitting end and thesecond surface, and the second surface having a mirror light reflectinglayer formed thereon; a light source module comprising: a first lightemitting component for providing light to the light incident end of thethird light guide component; and a second light emitting component forproviding light to the light incident end of the fourth light guidecomponent, wherein the first light emitting component and the secondlight emitting component are configured for emitting light alternately,the first surfaces of the first light guide component and the secondlight guide component are configured for guiding the light to thedetecting area; and an image detecting module disposed between twoneighboring ends of the first light guide component and the second lightguide component, and a field of view of the image detecting modulecovering the detecting area, the third light guide component and thefourth light guide component.
 2. The optical touch device as claimed inclaim 1, wherein each of the first light guide component and the secondlight guide component is a light guide bar, the light guide bar furtherhaving a light reflecting surface opposite to the first surface and alight incidence surface connected between the first surface and thelight reflecting surface, the first surface is a light emitting surface,and the light source module is further configured for providing light tothe light incident surfaces of the first light guide component and thesecond light guide component.
 3. The optical touch device as claimed inclaim 2, wherein the first light emitting component is disposed betweentwo neighboring ends of the second light guide component and the thirdlight guide component, the first light emitting component is furtherconfigured for providing light to the light incidence surface of thesecond light guide component, the second light emitting component isdisposed between two neighboring ends of the fourth light guidecomponent and the first light guide component, and the second lightemitting component is further configured for providing light to thelight incidence surface of the first light guide component.
 4. Theoptical touch device as claimed in claim 1, wherein each of the firstlight guide component and the second light guide component is a lightreflecting bar, the first surface of the light reflecting bar is a lightreflecting surface, the light source module further comprises a thirdlight emitting component disposed between two neighboring ends of thefirst light guide component and the second light guide component forproviding light to the detecting area, and the light reflecting bar isconfigured for reflecting the light arriving at the first surfacethereof to the detecting area.
 5. The optical touch device as claimed inclaim 4, wherein the third light emitting component is a light emittingdiode.
 6. The optical touch device as claimed in claim 1, wherein themirror light guide component is either a solid pillar or a hollowpillar.
 7. The optical touch device as claimed in claim 6, wherein themirror light guide component is a semi-cylindrical pillar, and the lightemitting end of the mirror light guide component is a curve surfaceadjacent to the second surface.
 8. The optical touch device as claimedin claim 1, wherein the mirror light guide component is hollow, and eachof the light incidence end and the light emitting end of the mirrorlight guide component is either an opening or a transparent layer. 9.The optical touch device as claimed in claim 1, wherein the secondsurface of the mirror light guide component is either a curve surface ora flat surface.
 10. The optical touch device as claimed in claim 1further comprising a substrate, wherein the light guide module and thelight source module are disposed on the substrate.
 11. The optical touchdevice as claimed in claim 1, wherein the first light emitting componentand the second light emitting component are respectively a lightemitting diode.
 12. A locating method for the optical touch device asclaimed in claim 1, the locating method comprising: controlling thefirst light emitting component and the second light emitting componentto emit light alternately, wherein the image detecting module detects afirst optical information when the first light emitting component islighted and the second light emitting component is closed, and the imagedetecting module detects a second optical information when the firstlight emitting component is closed and the second light emittingcomponent is lighted; and determining a position of a touch point in thedetecting area according to the first optical information and the secondoptical information detected by the image detecting module.